1. Field of the Invention
The present invention relates to a front vehicle frame structure. More specifically, the present invention relates to a front vehicle frame structure in which front side members and side frames are coupled together through a center cross frame.
2. Background Information
A front vehicle frame structure is a framework in which the engine of a vehicle is housed. An example of a front vehicle frame structure is described in Laid-Open Japanese Patent Publication No. 2001-310756. A front vehicle frame structure in this publication comprises a pair of left and right side frames, a cross member, sub frames, and brackets. The cross member has a seat for attaching an engine mount section and is arranged transverse between the left side frame and the right side frame. The sub frames are arranged respectively under the side frames and have their rear ends coupled to the corresponding side frames. The brackets couple each side frame and respective sub frame together at the respective coupling sections where the cross member and each of the side frames are coupled together.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved front vehicle frame structure. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
It has been discovered that, with the conventional front vehicle frame structure just described, there is a possibility that an impact load will be imparted disproportionately between the side frames and the sub frames when the impact load is imparted to the vehicle from the front. Moreover, when a larger proportion of the impact load is imparted to one of the side frames or one of the sub frames, there is a risk that that particular side frame or sub frame will deform in an unexpected manner. Consequently, the side frames and/or the sub frames will not absorb the energy resulting from the impact load in an intended manner.
The present invention was conceived in view of these circumstances. One of the objects of the present invention is to provide a front vehicle frame structure that can obtain a desired deformation mode and improve the efficiency with which an impact load imparted from the front of a vehicle is absorbed.
The forgoing object can be attained by providing a front vehicle frame structure that basically comprises first and second front side members, first and second side frames, and a cross center frame. The first and second front side members are arranged to extend in a front to rear direction of a vehicle. The first and second side frames are arranged to extend in the front to rear direction of the vehicle underneath the first and second front side members, respectively. The center cross frame has a first end section coupled to the first front side member and the first side frame, and a second end section coupled to the second front side member and the second side frame. The first and second side frames are vertically aligned with the first and second front side members, respectively. The first front side member is coupled to the first side frame at positions in front of the center cross frame and behind the center cross frame relative to the front to rear direction of the vehicle. The second front side member is coupled to the second side frame at positions in front of the center cross frame and behind the center cross frame relative to the front to rear direction of the vehicle.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.